Chapter 1 Caledonian igneous rocks of Great Britain - JNCC

Site selection criteria
Millour and Airdrie Hill Representative of outer, mantle-derived part of Criffel pluton, Galloway Suite.
Exceptional for mafic enclaves and foliation associated with emplacement.
Internationally important for studies of diapirism.
Ardsheal Hill and peninsula Representative and type area of Appinite Suite. Exceptional for range of ultramafic
to acid compositions and for breccia-pipes. Internationally important
for study of open system feeders to surface volcanism.
Kentallen Representative example of appinitic intrusion. Exceptional Mg- and K-rich
lithology, well-exposed contacts and complex age relationships.
Northern England Network, Chapter 4
Site name GCR selection criteria
Grainsgill Exceptional relationships of granite intrusion, greisen formation and mineralization
in Skiddaw Granite.
Shap Fell Crags Representative of Shap granite. Exceptional evidence for timing of Acadian
deformation. Internationally important for study of K-feldspar megacrysts.
Table 1.1c Silurian and Devonian Volcanic Rocks Block: networks and GCR site selection
criteria.
Scotland Network, Chapter 9
Site name GCR selection criteria
South Kerrera Representative of Lorn Plateau volcanic succession. Exceptional examples of
subaerial lava features and interaction of magma with wet sediment.
Ben Nevis and Allt a’Mhuilinn Representative of Ben Nevis volcanic succession. Exceptional intrusive tuffs.
Internationally important as example of exhumed roots of caldera, and historically
for development of cauldron subsidence theory.
Bidean nam Bian Representative of entire succession of Glencoe volcanic rocks. Exceptional
examples of ignimbrites, intra-caldera alluvial sediments and of sill complex
intruded into unconsolidated sediments. Internationally important historically
for development of cauldron subsidence theory and currently for evidence
of graben-controlled volcanism.
Stob Dearg and Cam Ghleann Representative of succession in eastern part of Glencoe caldera, including
basal sedimentary rocks. Exceptional rhyolites, ignimbrites and intra-caldera
sediments. Possible international importance for radiometric dating in conjunction
with palaeontology close to Silurian/Devonian boundary.
Buachaille Etive Beag Representative of Glencoe Ignimbrites. Exceptional exposures of pyroclastic
flows separated by erosion surfaces and alluvial sediments.
Stob Mhic Mhartuin Representative of Glencoe ring fracture and ring intrusion. Exceptional exposures
of crush-rocks and intrusive tuff.
Loch Achtriochtan Representative of Dalradian succession below Glencoe volcanic rocks.
Exceptional topographic expression of ring fracture and ring intrusion.
Crawton Bay Representative of Crawton Volcanic Formation.
Scurdie Ness to Usan Harbour Representative of ‘Ferryden lavas’ and ‘Usan lavas’, comprising lower part of
Montrose Volcanic Formation.
Black Rock to East Comb Representative of ‘Ethie lavas’, comprising upper part of MontroseVolcanic
Formation.
Balmerino to Wormit Representative of eastern succession of Ochil Volcanic Formation. Possible
international importance for radiometric dating in conjunction with palaeontology
close to Silurian/Devonian boundary.
Sheriffmuir Road to Menstrie Burn Representative of western succession of Ochil Volcanic Formation.
Exceptional topographic expression of Ochil fault-scarp.
Craig Rossie Representative of rare acid flow in upper part of Ochil Volcanic Formation.
Tillicoultry Representative of diorite stocks, intruded into Ochil Volcanic Formation, sur-
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